Directional phasing antenna configuration



2 Sheets-Sheet 1 EDWARD A. MORAN ATTORNEYS.

March 14, 1961 R. F. RIGGS ETAL DIRECTIONAL PHASING ANTENNA CONFIGURATION Filed May 5, 1960 DIRECTIONAL PHASING ANTENNA CONFIGURATION 2 Sheets-Sheet 2 Filed May 5, 1960 OUTPUT O OOUTPUT MAxlMUM MAXIMUM OUTPUT O MAXIMUM ("1 FIG. 5

INVENTORS.

ROBERT F. RIGGS HENRY LEE FOSTER JR. EDWARD A, MORAN United States Patent O y f' DIRECTIONAL PHASING ANTENNA CONFIGURATION Robert F. Riggs, Charlottesville, Va., and Henry L. Foster, Jr., Pomona, and Edward A. Moran, Norco, Calif., assignors to the United States of America as represented by the Secretary of the Navy and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to antenna structures and `particularly to a directional phasing antenna configuration.

The present invention is an improvement over the hybrid-junction type of antenna which requires two antenna elements mounted on a ground plane, and which is described in U.S. patent application Serial No. 818,978, filed June 8, 1959. This antenna configuration is much more effective than previous configurations, having much less shielded area since the antenna elements are mounted within a cylindrical metal housing which also serves as the outer shell of the device and serves the same purpose as the hybrid-junction in the previous type antenna; also, the present antenna has a much simpler and less bulky arrangement than the hybrid-junction type antenna.

It is an object of the invention therefore to provide a new and improved directional phasing antenna configuration.

Another object of the invention is to provide a directional phasing antenna configuration that is of simpler construction, has less bulky arrangement and is much more `effective than previous similar purpose antennas.

A further object of the invention is to provide a novel phase-sensitive device.

Other objects and many of the attendant advantages of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Figure l is side view, partially cutaway, of a preferred embodiment of the invention.

Figure 2 is a top view of the embodiment of Figure 1.

Figure 3 is a cross-sectional View taken along line 3--3 of Figure 2. i

Figure 4 is a cross-sectional View taken along line 4-4 of Figure 2.

Figure 5 shows curves representing detected video outputs from the antenna dipoles.

Referring now to the drawings like numerals refer to like parts in each of the ligures.

A cylindrical housing of copper or other suitable metal is used as a ground plane and to house the antenna assembly. A coaxial waveguide section, having an outer conductor 12 and center condutcor 14, is mounted within housing 10 by means of end closures 16 and` 1S such that it is positioned off center and closer to one side of housing 10 than the other. Dipolev antennas 20 Vand 22 are mounted perpendicular to center conductor 14 at 24 and 2S respectively and extend beyond the housing 10 passing through respective apertures 26 and 27 in conductor 12 and apertures 28 and 29 in housing 10 where the coaxial waveguide is nearest to the housing. The diameter of the apertures is determined by the desired impedance. Dipole antennas and 22 extend one-fourth wavelength (M4) Patented Mar. 14, 1961 distance beyond the outer surface of housing 10; the dipoles are cut to extend beyond the housing a suitable length as is determined for S-band frequencies and polarization patterns. Also, dipoles 2i) and 22 are spaced apart along the length of the antenna assembly approx imately one-half wavelength (M2) for S-band frequencies; \=Wave length of propogation. Center conductor 14 thus serves as a support for the dipoles; it also serves as an -air coaxial transmission line tapped for outputs at 30 and 32.

The feedpoints for dipoles 20 and 22 are respectively at 30 `and 32. Terminals 34 and 36 extend perpendicular from center conductor 14 in an opposite direction from the dipoles and through dipole feed apertures 37 and 38, respectively, in coaxial conductor 12. 'Coaxial cable dipole transmission lines 40 and 42 have their center conductors soldered to terminals 34 and 36 respectively and their outer conductors soldered to outer conductor 12 of the coaxial waveguide section. Coaxial cables 40 and `42 extend beyond the housing 10 through end closure 16. Beyond the end closure 16 coaxial cables 40 and 42 each have a protective dielectric sheath 46 thereabout. The coaxial cable transmission lines are connected to microwave detectors, not shown, which `are used in accomplishlee ing algebraic video summing by comparing the negative' and positive yield thereof. Usually one transmission line would be connected to `a normal bias S-band detector and the other line connected to a reverse bias S-band detector. This antenna configuration is also applicable for frequencies of other desired bands by using suitable dimensions for the antenna assembly components.

The present device operates such that the amplitude of the output lthereof is dependent upon the position of the antenna with respect to `the radiating source and the arnplitude of signals received by the antenna. Positive .and negative detected pulses can then be compared, by some suitable means, to give an output whose polarity is dependent upon the position of the antenna with respect to the radiating source. The gain of the antenna assembly may be low because of close proximity to radar radiations of great magnitude and yet deliver pulses of sufficient amplitude.

The curves shown in Figure 5 represent the individual lobes of each dipole antenna, 20 and :22, and also the theoretical and final yield of the directional phasing antenna assembly. The curves shown are for when the antenna configuration is in an S-band R.F. field of suitable strength for video signal detection. Zero degrees is determined When the antenna configuration is in a position approximately parallel to the earth and oriented such that long axis of the antenna configuration points toward the .radiating source, and is located Within an effective range from the radiating source. At andv 270 is shown the output when the antenna configuration has been rotated to Where it is at right angles to the radiating Y Curve A, Figure 5,v shows the detected positive video output without any attenuation in the transmission line; the output is developed from dipole 20. Curve B shows the detected negative video output, as developed from dipole 22, without any attenuation in the transmission line. Curves C and D represent the detected Video outputs when, for example, approximately 6 decibels of attenuation has been placed in the transmission lineV of dipole 20 and 3 decibels of attenuation has been placed in the transmission line of dipole 22. Curve E represents the theoretical output of the antenna configuration before algebraic summing thereof. actual output of the antenna configuration when the aforementioned attenuation, for example, has been placed in the respective transmission lines; with these Curve F represents the' attenuatons ythe positive width is approximately il at 90 and 270. Without any attenuation the positive Width would be approximately i30 at 90 or 270. Obviously many .modifications and.variations of the present invention are possible in the light of the above teachings. VIt is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1,. A directional phasing antenna configuration cornprising a metal housing having a section of coaxial transmission line mounted therein such that one side of said coaxial transmission line lies nearer to one side of said housing than the remainder thereof, a pair of antenna dipoles of desired length supported by the center conductor of said section of coaxial transmission line and extending perpendicularly therefrom through respective apertures in the outer conductor of said section of coaxial transmission line Yand said housing, said antenna dipoles extending beyond said housing a distance as determined by the desired frequency and polarization patterns for the antenna conguration, feedpoint means extending from said center conductor through respective apertures in said outer conductor and connected to respective coaxial cable transmission lines, said coaxial cable transmission lines being connected to means for comparing signals from said feedpoint means.

V2. A directional phasing antenna configuration comprising a cylindrical metal housing being closed at each end and having a section of coaxial transmission line mounted therein atthe ends thereof such that one side of said coaxial transmission line along the length thereof lies nearer to one side of saidV housing than the remainder thereof, a pair of antenna dipoles of desired length mounted on the center conductor of said section of coaxial transmission line and extending perpendicularly therefrom through respective apertures in the outer conductor of said section of coaxial transmission line and said housing, said dipoles extending out beyond said housing and spaced apart distances determined by the desired frequency and polarization patterns for the antenna coniguration, a pair of dipole feedpoints positioned along 4 Y said center conductor and terminals extending therefrom away from said dipoles through apertures in said outer conductor to connect with respective coaxial cable transmission lines which are connected to means for comparing signals.

3. An antenna configuration as in claim 2M wherein said apertures through which said dipoles extend being positioned along the length of the antenna configuration where said section of coaxial transmission line is nearest to the longitudinal wall of said housing. Y

4. An antenna configuration as in claim 2 wherein said dipoles are positioned at one-fourth and three-fourths distances, respectively, along the length of said section of coaxial transmission line.

5. An antenna configuration as in claim 2 wherein said feed-point terminals are positioned lat Yone-fourth and one-half distances, respectively, along the length of said section of vcoaxial transmission line from the end thereof.

6. An antenna coniiguration as in claim 2 wherein said dipoles extend out beyond said housing a distance equal to one-fourth the desired wavelength for the antenna.

7. A directional phasing antenna configuration comprising a metal housing having a section of coaxial transmission line mounted therein at the ends thereof such that one side of said coaxial transmission line along the length thereof lies nearer to one side of saidhousing than the remainder thereof, a pair of antenna dipoles of desired length mounted on the center conductor of said section of coaxial transmission line and extending perpendicularly therefrom through respective apertures in the outer conductor of said section of `coaxial transmission line and said housing, said dipoles extending beyond said housing and spaced apart distances determined by the desired frequency and polarizationpatterns for the antenna configuration, a pair of feedpoints for said dipoles along said center conductor and terminals extending therefrom through apertures in said outer conductor to connect with respective coaxial cable transmission lines which are connected to means for comparing signals therefrom.

No references cited. 

